Radiation imagery chemistry: process – composition – or product th – Diazo reproduction – process – composition – or product – Composition or product which contains radiation sensitive...
Reexamination Certificate
2000-12-22
2003-03-25
Chu, John S. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Diazo reproduction, process, composition, or product
Composition or product which contains radiation sensitive...
C430S270100, C430S326000, C430S905000, C430S176000, C522S031000, C522S032000
Reexamination Certificate
active
06537718
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a positive photosensitive composition for use in the production of a lithographic printing plate, a semiconductor such as IC, a circuit board for liquid crystal and thermal head and in other photofabrication processes.
BACKGROUND OF THE INVENTION
As the photosensitive composition for use in the production of a lithographic printing plate, a semiconductor such as IC, a circuit board for liquid crystal and thermal head and in other photofabrication processes, various compositions are known and photoresist photosensitive compositions are ordinarily employed. The photoresist compositions are widely divided into positive photoresist compositions and negative photoresist compositions.
One of the positive photoresist photosensitive compositions is a chemical amplification-type resist composition as described in U.S. Pat. No. 4,491,628 and European Patent No. 249,139. The chemical amplification-type positive resist composition is a pattern formation material which generates an acid in an exposed area upon irradiation with a radiation such as a far ultraviolet ray and due to a reaction using the acid as a catalyst, solubility in a developing solution differentiates in the area irradiated with the active radiation from the non-irradiated area to form a pattern on a substrate.
Examples of such a resist composition include combinations of a compound capable of generating an acid by photolysis with an acetal or O,N-acetal compound as described in JP-A-48-89003 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”), with an ortho ester or amide acetal compound as described in JP-A-51-120714, with a polymer having an acetal or ketal group on the main chain as described in JP-A-53-133429, with an enol ether compound as described in JP-A-55-12995, with an N-acyliminocarbonic acid compound as described in JP-A-55-126236, with a polymer having an ortho ester group on the main chain as described in JP-A-56-17345, with a tertiary alkyl ester compound as described in JP-A-60-3625, with a silyl ester compound as described in JP-A-60-10247 or with a silyl ether compound as described in JP-A-60-37549 and JP-A-60-121446. These combinations exhibit high photosensitivity since they have in principle a quantum yield exceeding 1.
A system which is stable at a room temperature but decomposes by heating in the presence of an acid to become alkali-soluble is also known and examples thereof include combinations of a compound capable of generating an acid on exposure with an ester or carbonic acid ester compound having a tertiary or secondary carbon (e.g., tert-butyl or 2-cyclohexenyl) as described, for example, in JP-A-59-45439, JP-A-60-3625, JP-A-62-229242, JP-A-63-27829, JP-A-63-36240, JP-A-63-250642,
Polym. Eng. Sce.,
Vol. 23, page 1012 (1983),
ACS. Sym.,
Vol. 242, page 11 (1984),
Semiconductor World,
November, 1987, page 91,
Macromolecules,
Vol. 21, page 1475 (1988), and
SPIE,
Vol. 920, page 42 (1988). Since such a system has high photosensitivity and a little absorption in a far ultraviolet region, it is suitable for ultra fine fabrication using a light source having a shorter wavelength.
In general, the chemical amplification-type positive photoresist composition is roughly divided into two types. Specifically, there are a chemical amplification positive photoresist of three-component type comprising an alkali-soluble resin, a compound capable of generating an acid upon irradiation with a radiation (hereinafter also referred to as a “photo-acid generator” sometimes) and a compound which has an acid-decomposable group and prevents the alkali-soluble resin from dissolution and a chemical amplification positive photoresist of two-component type comprising a resin having a group capable of being decomposed by a reaction with an acid to become alkali-soluble and a photo-acid generator.
The two-component or tree-component chemical amplification positive photoresist composition is subjected to exposure to generate an acid from the photo-acid generator, heat treatment and development thereby obtaining a resist pattern.
These photoresist compositions, particularly photoresist compositions for exposure to a far ultraviolet ray still have problems in the properties such as line edge roughness and micro grain (an extraneous substance on the surface of a resist film) which are desired to be solved. The line edge roughness means unevenness of edge which occurs at an edge between a line pattern of resist and a surface of a substrate irregularly fluctuates in a direction vertical to the line due to the characteristics of resist, when the pattern is observed from just above. The unevenness is transferred in an etching step in which the resist acts as a mask and thus, electric properties are damaged thereby decreasing yield. The occurrence of micro grain results in degradation of reproducibility in the etching step thereby decreasing yield.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a positive photoresist composition for exposure to a far ultraviolet ray which is improved in line edge roughness and micro grain, which is excellent in uniformity of a resist film formed and which has less particles in its resist solution.
Other objects of the present invention will become apparent from the following description.
As a result of intensive investigations made by the inventors on materials for the chemical amplification-type positive photoresist compositions, it has been found that the objects of the present invention are successfully accomplished by using a specific acid-decomposable resin and a specific mixed solvent described below to complete the present invention.
Specifically, the present invention includes the following positive photoresist compositions:
(1) a positive photoresist composition for exposure to a far ultraviolet ray which comprises (A) a compound which generates an acid upon irradiation with an actinic ray or radiation, (B) a resin which contains a repeating unit corresponding to hydroxystyrene and solubility of which increases in an alkaline developing solution by the action of an acid, and (C) (1) at least one solvent selected from the group consisting of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether propionate, and (2) at least one solvent selected from the group consisting of propylene glycol monomethyl ether and ethoxyethyl propionate,
(2) the positive photoresist composition for exposure to a far ultraviolet ray as described in item (1) above, wherein the composition further comprises at least one solvent selected from the group consisting of &ggr;-butyrolactone, ethylene carbonate and propylene carbonate, and
(3) the positive photoresist composition for exposure to a far ultraviolet ray as described in item (1) above, wherein the resin (B) contains a repeating unit represented by formula (IV) shown below and a repeating unit represented by formula (V) shown below:
wherein L represents a hydrogen atom, a straight-chain, branched chain or cyclic alkyl group which may be substituted or an aralkyl group which may be substituted; Z represents a straight-chain, branched chain or cyclic alkyl group which may be substituted or an aralkyl group which may be substituted; or Z and L may be combined with each other to form a 5-membered or 6-membered ring.
DETAILED DESCRIPTION OF THE INVENTION
The compounds for use in the photoresist composition of the present invention will be described in greater detail below.
<(A) Compound Which Generates an Acid Upon Irradiation with an Actinic Ray or Radiation (Photo-acid Generator)>
The photo-acid generator (A) for use in the present invention is a compound which generates an acid upon irradiation with an actinic ray or radiation.
The photo-acid generator for use in the present invention can be appropriately selected from photo-initiators for photo-cation polymerization, photoinitiators for photo-radical polymerization, photo-achromatizing agents for dyes, photo-discoloring agents, known co
Fujimori Toru
Nishiyama Fumiyuki
Chu John S.
Fuji Photo Film Co. , Ltd.
Sughrue & Mion, PLLC
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